Any car mechanics

[Pin-seeker]

I could be wrong,but isn't the MOT just to check that the vechile is Safe to drive on the roads & emissions are ok?
You wouldn't get a warning that it struggled to start or battery is on its way out.
Maybe the mechanic would mention it but that's about it.

 

[MadAdey]

Not strictly true, there is no "alternator circuit" thats separate to the battery. If the battery is of low charge then the alternator feeds through the battery needing to bring the battery charge level up. Hence the need to run a car with a flat battery for a whle once started, to let the alternator feed the battery to increase its charge.

The alternator does not feed through the battery. The battery sits on the cars electrical system that is supplied from the alternator, hence why a car with a dodgy battery will run fine once it has been started. That electrical system will sit at around 14v and it is that, that recharges the battery. If you don't believe me disconnect your battery and jump start your car, it will run fine, you will just be buggered when you try and re start it.

 

[GreiginFife]

The alternator does not feed through the battery. The battery sits on the cars electrical system that is supplied from the alternator, hence why a car with a dodgy battery will run fine once it has been started. That electrical system will sit at around 14v and it is that, that recharges the battery. If you don't believe me disconnect your battery and jump start your car, it will run fine, you will just be buggered when you try and re start it.

And you are of course correct which is why I said strictly not true. That system you speak of is a circuit, of which the battery is part, and why an engine wont start if it is removed, unless it is bridged to another. It is one circuit, not 2 separate ones was my point.

I have had many problem battery cases pass through my little back yard garage, many differing symptoms. But they all start from one place, the car beind dead.
No one has tried to cover off the fact that the car was, infact, dead and needed jumped in the first place. No spark plug fault or cracked head would flatten a battery.

So assuming that Mrs Fish didnt leave a light jn ivernight or the stereo on, the battery died of its own accord. Doesnt sound like a healthy battery in that case...

Or do you know of something that would?

 

[Foxholer]

The alternator does not feed through the battery. The battery sits on the cars electrical system that is supplied from the alternator, hence why a car with a dodgy battery will run fine once it has been started. That electrical system will sit at around 14v and it is that, that recharges the battery. If you don't believe me disconnect your battery and jump start your car, it will run fine, you will just be buggered when you try and re start it.

I believe that is the difference between having something wired in Parallel and having it wired in Series! Battery and Alternator are wired in parallel, so whichever is active/dominant is the one that feeds the rest of the circuit. So battery starts it, then alternator takes over and, as it's a slightly higher voltage, charges the battery.

 

[MadAdey]

Hope the list you've made sorts it out. If I was going to try and sort this without wasting the cost of a new driver at the local garage it would go like this:

1) find somewhere that will do a free battery health check as that will check out the alternator and the diodes too.
2) check inside the oil cap and make sure there is no leak from the coolant system.
3) get a plug puller and take a look at them.
4) disconnect the HT leads at both ends and continuity check them, make sure there is not a high resistance on them causing a drop in voltage.

 

[sev112]

Fabulous thread - just like Ball flight laws etc but on cars
Hope you get it sorted Fish.

my 02 focus diesel has for the past 3 years been temperamental, since I took her up a glacier in Switzerland, but also since the mrs got a new small car and the focus does about 10 miles a week tops, which is no doubt the real issue,

 

[MadAdey]

I believe that is the difference between having something wired in Parallel and having it wired in Series!

Exactly, the battery in your car is wired parallel to the electrical system, not in series.

 

[bobmac]

So I drove her to her work the 0.8 miles

Buy her a bike

 

[Slime]

Hi Fish, this would be my checklist for your garage..

1. Get the garage to do a voltage drop test on the battery just to rule that one out.

2. Check the coolant temperature sensor. If the car thinks the coolant is warm, when trying to start the car from cold, the fuel mixture will be too lean, making the car hard to start and lumpy until warm ........................ if that makes sense.

3. Get the garage to inspect the throttle body/mass air flow meter. (Common Micra problem). They can get choked up with lots of short runs but usually, when faulting, run better when cold than when warm. If that's the issue, get one on-line as Nissan charge a fortune for them!

4. Check the distributor, they are prone to failure!


I honestly don't think it's the battery, but easy to rule out with a drop test, and an oil and filter change is very strongly advised, particularly considering it's life style.

Let us know how you get on,


Slime.

P.S. Just had an oil/filter change on my Freelander for the first time in about four years ............... quelle difference!
It's quicker, runs cleaner, runs cooler and is more economical!

 

[CliveW]

I am currently watching a thread about curing a slice on Pistonheads... Strange how many "experts" are on there too!

 

[DanFST]

I'd say more like a sunny.

Skyline ?

Actually a Silvia! Very close tho.

 

[DanFST]

Was the cause found?

 

[Fish]

Its not gone in yet but is working and starting fine, even after not being used for over 2-days, no sign of the lumpyness since I gave it a god run down the A45 for a few miles either!

 

[philly169]

I had issues with my battery over xmas, really struggled to start but once up it was fine. Cold weather didn't help. Went to Halfrauds for a new battery and for them to fit it but they couldn't undo the nut so wouldn't do it.

In the end I did it myself, but was an issue but after an hour and a half battle I got it out. New battery in and it starts straight away.